Dishwashers with devices for filling level recognition are known wherein the fluid level is detected by mechanical means, for example, by floats. In devices of this type, the float floats on the liquid surface as soon as the fluid level in the dishwasher exceeds a certain level. The float is usually mechanically connected to a switch which changes its switching position as a result of the floating movement of the float and passes a corresponding signal to the program control of the dishwasher.
Other systems for detecting the fluid level in a dishwasher work by using a pressure capsule in a communicating pipe system which is compressed as the fluid level rises. The fluid level in the dishwasher can be determined from the extent of the compression of the pressure capsule. The known systems for filling level recognition have the disadvantage that they have a number of mechanically moveable parts which are liable to wear and contamination, for example, by deposited dishwashing residue which can result in tolerance problems to the extent of complete failure of the device for filling level recognition.